Hi,
With Exchange 2007 it was possible to backup the passive node and active node only in case of problem. With Exchange 2010 we have to make a full backup of the active database and a copy of the passive. I cannot see any way to avoid this new strategy.
For me there are two big problem:
1- the backup consumes resources on Exchange by backing up active node
2- we must at least double the space dedicated to the backup... or triple if we had a third server into the Exchange DAG. It's VERY expensive.
(Even if I could read that the copy takes less space than the full backup, by testing I can see exactly the same space used by replica and RP by each databases into the 2 servers of the DAG)
3- when the role change into the DAG, the backup admin must be aware to change the strategy for the full backup and copy.
I read this topic: http://social.technet.microsoft.com/Forums/en-US/dpmexchbackup/thread/e76d57a5-5536-4c43-95b8-ea2a636ba054 where
we can see: "it is recommended that you protect at least two copies of the DB"
OK, and it's probably better to have 3 copies and, why not, 10 copies :-D Seriously, I understand this recommendation but I have a question: what happens if we have a third-party
software to manage the archiving?
At the end, we have 2 servers for Exchange, DPM and a archiving tool, it means that we have to buy disk to store 5 copies of a database (2 into DAG, these 2 are backed up by DPM and on for the archive). Someone will probably answer that we can avoid it by moving all databases on only one node... but in this case we lose the most important improvement with the DAG: the opportunity to have 2 servers active in parallel to share the load.
Finally, I want to know if there is a way into DPM to avoid the copy and keep only a full backup and/or is there improvements to wait about it into DPM and/or Exchange?
Regards :)